This application relates to a staged flat flame oxy-fuel burner, and in particular, a staged flat flame oxy-fuel burner capable of achieving much lower firing rates than presently existing burners.
Staged flat flame oxy-fuel burners are known, including the burner described in U.S. Pat. No. 5,611,682, which is incorporated herein by reference in its entirety. Flat flame oxy-fuel burners without staging are also known, including the burner described in U.S. Pat. No. 5,575,637, which is incorporated herein by reference in its entirety. Both of these patents are owned by the assignee of the present application.
Extending the '682 and '637 patent designs to low firing rate applications is not a straightforward problem, and attempts to simply scale down the geometry of the burner have not been successful. In particular, one challenge has been preventing the burner block from overheating at low firing rates while producing a stable and luminous flame desired for glass melting. This balance has been especially elusive in burners designed using on standard scale-up/down rules to make a small scale flat flame oxy-fuel burner with oxygen staging based on the design principles of larger burners as described in the '682 and '637 patents.
The present application relates to a design approach and a resultant burner having a geometry and operating parameters that prevent burner block overheating throughout the entire operating range due to a systematic selection of the relative and absolute dimensions of the precombustor and fuel and oxygen nozzles.